混合组网环境下VLAN互通问题及实现

介绍了异构网络设备在VLAN实现上的差异，研究和实现了混合组网环境下异构网络设备之间的VLAN互通的问题，为校园网的资源整合和利用提供借鉴。     

加热对蜂蜜中羟甲基糠醛含量的影响

目的研究加热过程对不同种类蜂蜜中羟甲基糠醛(HMF)含量的影响。方法采用比色法对蜂蜜在不同加热温度和加热时间下HMF含量变化进行测定。结果随着加热温度的升高和加热时间的延长,蜂蜜中HMF含量变化较大,不同种类蜂蜜中的HMF含量变化情况也不相同,且温度越高,HMF产生的速率越快。结论要使蜂蜜中HMF含量符合标准,热加工处理温度应低于 80℃。     

Purification of breast cancer resistance protein ABCG2 and role of arginine-482

Human ABCG2 was efficiently overexpressed in insect cell membranes, solubilized with 3-[(3-cholamidopropyl)dimethyl ammonio]-1-propanesulfonate, and purified through N-terminal hexahistidine tag. Its functionality was assessed by high vanadate-sensitive ATPase activity, and nucleotide-binding capacity. Interestingly, the R482T point mutation increased both maximal hydrolysis rate and affinity for MgATP, and lowered sensitivity to vanadate inhibition. Direct nucleotide binding, as monitored by quenching of intrinsic fluorescence, indicated a mutation-related preference for ATP over ADP. The R482T mutation only produced a limited change, if any, on the binding of drug substrates, indicating that methotrexate, on the one hand, and rhodamine 123 or doxorubicin, on the other hand, bound similarly to wild-type and mutant transporters whether or not they were subject to cellular transport. In addition, the characteristic inhibitors GF120918 and 6-prenylchrysin, which alter mitoxantrone efflux much better for wild-type than mutant ABCG2, bound similarly to purified ABCG2, while the highly-potent Ko143 bound in the nanomolar range also effective in inhibition of drug transport. All results indicate that the role of the arginine-482 mutation on substrate drug transport and inhibitor efficiency is not mediated by changes in drug binding. Received 10 April 2006; received after revision 22 May 2006; accepted 12 June 2006 A. Pozza and J. M. Perez-Victoria contributed equally to this work     

Oxidative photochemical decarboxylation of zaragozic acid A

A unique decomposition reaction of the novel squalene synthase inhibitors called zaragozic acids has been studied. Under very mild conditions, e.g. by merely exposing their solutions to air and visible light at ambient temperature, these compounds, characterized by the 2,8-dioxabicyclo[3.2.1]octane-4,6,7-trihydroxy-3,4,5-tricarboxylic acid core, rapidly decompose. As relatively stable intermediates in the cascade of decomposition, the biologically active 2,8-dioxabicyclo[3.2.1]octane-6,7-dihydroxy-4-keto-5-caroxylic acid (or 3,4-decarboxy-4-dehydro) derivatives of these compounds have been isolated in ca. 20% yield. Derivatization on the highly reactive 4-carbonyl group yields stable derivatives, several of which are potent inhibitors of squalene synthase. Further decomposition results in the elimination of C3 and C4 atoms and the carboxylic acid on C5, the oxidation of C5 to carboxylic acid and the liberation of the oxo group on C1. Specific results obtained with zaragozic acid A, a key representative of the family of these potent cholesterol-lowering agents, are presented in this study.     

5′-磷酸吡哆醛高分子衍生物的辅酶功效

5′-磷酸吡哆醛(PLP)与经β-硫酸酯乙砜基苯胺活化的聚乙二醇(PEG)或右旋糖酐(Dx)共价结合,得可溶性5′-磷酸吡哆醛衍生物。用PLP-PEG和PLP-Dx衍生物代替PLP作为谷氨酸脱羧酶的辅酶,谷氨酸脱羧酶活力回复率达18%左右;用甘氨酸封闭的PLP-PEG代替PLP作为辅酶,谷氨酸脱羧酶活力回复率达44%。     

Evidence for the presence of virus in clonal insulin-producing RINm5F cells

Summary The ultrastructural morphology of the clonal insulin-producing cell line, RINm5F, was investigated. Virus-like particles, probably C type viruses, were identified both intra- and extracellularly. Because these particles could not be found in the original transplantable tumor, it is probable that viruses were induced at some later stage in the development of the RINm5F cell line. All investigators using the RINm5F cells should be aware of the fact that these cells may contain one or several types of viruses, and of the possibility that these particles may interfere with a variety of cellular functions.This work was supported by grants from the Lake County Medical Center Developmental Agency (to VH and PWB) and the American Heart Association, Indiana Affiliate (to PWB,^*USA) and by the Swedish Medical Research Council (12X-562), the Swedish Diabetes Association, the Nordic Insulin Foundation and Åke Wibergs Foundation (^**Sweden). Per-Olof Berggren is a recipient of a postdoctoral fellowship from the Swedish Medical Research Council.     

指示生物测评污水厂净化能力的研究

为了利用指示生物来监测和评价污水厂处理效果,在不同的水质情况下对指示生物的种属、数量、活性及其组成和数量进行了检测与分析,结果表明,通过检测污水厂曝气池中纤毛虫组合率可以预报出水水质情况;观察与监测指示生物的生物相和生长变化情况能及时反应水厂运行的异常情况.据此能够及时指导污水处理厂的生产运行,保证污水厂的处理效果.     

含氯取代基的双酚A型聚芳酯的相转移催化合成

本文以对苯二甲酰氯(TPC)、2、5-二氯对苯二甲酰氯(DCC)、双酚A(BPA)为原料,采用相转移催化界面缩聚法合成了含氯取代基的双酚A型聚芳酯.考察了催化剂用量、NaOH用量和单体组成对聚合反应的影响,并用红外光谱、X-射线衍射、差示扫描量热及热失重等对共聚物进行了表征.研究表明随着DCC与TPC的摩尔比增加,共聚物的熔点和结晶度都逐渐降低,共聚物具有优异的耐热性.     

用作桥联配体的4,4′-二苯基-2,2′-双噻唑-5,5′-二磺酸钠的合成

以二硫代乙二酰胺、ω一溴代苯乙酮为起始原料 ,用无水乙醇作溶剂合成了 4,4′-二苯基 - 2 ,2′-双噻唑 .m.p.2 1 6.9℃～ 2 1 7.1℃ ,收率 5 7.5 % .IR,νmax( cm- 1 ) :31 1 1 (芳杂环 C- H) ,30 60(芳氢 ) ,1 5 97,1 5 5 8,1 5 4 1 ,1 5 0 8,1 474,1 44 3(苯环骨架 ,噻唑环骨架振动 ) ,939,742 ,692 (苯环单取代 ) .后经磺化 ,中和生成 4,4′-二苯基 - 2 ,2′-双噻唑 - 5 ,5′-二磺酸钠 .m.p.大于 30 0℃ ,收率 44% .IR,νmax( cm- 1 ) :1 2 36,1 1 84,1 1 2 6,1 0 4 7( R- SO3- ) .1 HNMR,δ( ppm) :7.63,7.5 6,7.5 1 (苯 H)     

＜运动心理技能量表＞心理测量特征的检验

＜运动心理技能量表（ＰＳＩＳＲ－５））是一个由４５道测题组成的，旨在对与运动表现有关的６种心理技能进行测量的心理测试工具．本研究以四种运动水平的中国运动员为被试，对ＰＳＩＳＲ－５的一些心理测量特征进行了检验．６个分量表内部一致性的检验结果均低于最低应用标准，各分量表间的相关分析结果也难以令人满意，而且因素分析的结果也并不十分支持该量表的因素效度．基于以上结果，有必要对ＰＳＩＳＲ－５进行更进一步的研究．